Ventilation and clearance of the middle ear and the Eustachian tube function

The Eustachian tube (ET) has an important role in pressure equilibration, protection and clearance of the middle ear (ME). Dysfunction most commonly may present with a sensation of blocked ears, pressure, serous otitis media, tympanic membrane retraction (or hyperinflation), cholesteatoma and chronic ear drum perforation. ET function has been studied extensively in different conditions, in normal individuals and in patients with ME diseases using multiple methods. The results of these measurements are many times contradicting. In this review we aim to describe the various mechanisms involved in physiologic and pathophysiologic states involving the middle ear cleft, which may explain the confounding and variable results. We suppose that these mechanisms act according to the situation in which the individual is at that time. This variability leads to the confusing contradictory test results.